The present invention relates to a method for supporting mobility in the internet.
In networks today, the supporting of mobility is only possible in dedicated areas of a network and is thus very limited. To support unlimited subscriber mobility (personal mobility), enhanced network mechanisms are required. This assumes a subscriber who is registered as a subscriber with one or more Internet Service Providers (ISPs), or, corporate networks. Mobility refers to the movement of the subscriber across network boundaries; that is, even into networks of random other ISPs or companies.
The present invention provides a method for supporting personal mobility which makes possible the availability of services at terminals which are connected in principle to arbitrary access nodes for the Internet. To characterize personal mobility, the subscriber has an identifier (identification), which can be represented by logical addresses, for example, similar to those used in an e-mail format. Basically, it should be possible to use universal (that is, not specially configured) terminals, such as standard PCs in hotel rooms, conference rooms or Internet cafes, or portable notebooks.
In the Internet, and within the Internet Engineering Task Force (IETF), two methods are known which enable limited mobility:
a) roaming capabilities (roaming operations working group within IETF): roaming agreements between ISPs enable Internet access to the local dial-in nodes of the contracting ISPs;
b) terminal mobility (mobile IP working group within IETF): enables mobility between local networks (LANs) which are connected via the Internet, with a terminal having a strictly assigned address moving from one location to another (see C. Perkins, xe2x80x9cMobile IPxe2x80x9d, IEE Communications Magazine, May 1997, pp.84-99).
However, the above methods described in a) and b) support only limited mobility:
a): This method only offers support with respect to authentication and billing. It opens access to foreign ISPs, but only with the services provided there. In this case, the subscriber is assigned a temporary address, which is not directly known either in the home network or anywhere else in the Internet; that is, it is not possible to receive messages or to use services without first having given one""s temporary address to the respective communication partner.
b): In this method, the foreign network must be a LAN. The terminal used must be configured specifically for mobile IP. The terminal is permanently connected to a specific address from the home network. For several home networks, a separate configuration is respectively required. Therefore, there is no flexibility here with respect to a free selection of terminal equipment.
It is the object of the invention to guarantee the complete supporting of mobility.
This object is inventively achieved in accordance with the present invention in a method for supporting mobility in the Internet, the method comprising the steps of: providing a terminal that is not connected to a home network of a subscriber; inputting a subscriber identification for the subscriber via the terminal; and providing service readiness of the terminal for the subscriber by interrogating an IP address for the subscriber at a server agent in the home network of the subscriber by an Internet access component with the aid of the subscriber identification.
In an embodiment, the interrogated IP address is transferred to a proxy node component of the terminal; and a communication relation is set up to a home agent of the subscriber in accordance with the protocol of mobile IP.
In an embodiment, the communication relation to the home agent of the subscriber is set up via a foreign agent.
In an embodiment, the server agent is obtained with aid of the domain name system.
In an embodiment, the interrogated IP address is assigned to the terminal by the proxy node component.
In an embodiment, a local IP address is assigned to the terminal by the proxy node component.
This object is also inventively achieved in accordance with the present invention in a server agent in a home network of a mobile subscriber, said server agent comprising: a transmitter for returning an IP address which said server agent links to a subscriber identifier of said mobile subscriber given a request by an Internet access component of a foreign network by which the IP address for the mobile subscriber is requested from within the foreign network upon provision of the subscriber identity.
In an embodiment, the server agent further comprises: an address pool from which, upon receiving a request of an Internet access component of said foreign network, said server agent is further for making available an IP address from an address pool for said subscriber identifier that was given in said request and for transmitting said IP address to said Internet access component; and an association table in which said server agent stores said allocations between said subscriber identifier and IP address.
In an embodiment, the address pool comprises at least one of real IP addresses and virtual addresses for dynamic addressing.
This object is also inventively achieved in accordance with the present invention in an Internet access component comprising a request means for making a request for an IP address at a mobile subscriber""s home agent for the mobile subscriber, which request is characterized by a subscriber identifier.
In further embodiments, in a protocol and a method for supporting mobility, an IP addressed is exchanged between an Internet access component and a server agent.